In many chemical extraction processes, oil based substances and aqueous solutions are mixed for various reasons. In most cases these oil based substances must be recovered for economical and environmental concerns. The aqueous solution must be cleaned of suspended solid contaminates as well as entrained oil before the aqueous solution is reused in the process or returned to the aquifer. If the aqueous solution is to be dumped into an ocean, stream or municipal treatment system, high environmental standards must be maintained. Stringent governmental laws and environmental concerns have increased the need for such equipment in a wide variety of industries and applications. This invention is capable of sustained operation in high turbidity applications and has excellent oil recovery efficiencies and suspended solids removal abilities.
The purpose of this invention is to provide industry with cost effective coalescing equipment for use in various applications that are subject to unusually high concentrations of suspended solids. A coalescer that requires a minimum amount of maintenance on a yearly basis. A separator capable of selectively removing suspended solids pre and post coalescing media for separating immiscible liquids on a continuous basis. A coalescer designed with a removable coalescing media pack which can be easily removed from the vessel and re-installed in a nominal amount of time. A coalescer that has means for automatically cleaning the coalescing media of accumulated solids at predetermined intervals.
1. Field of the Invention
This invention relates generally to the field of coalescing and more particularly to an apparatus for the removal of suspended solids and entrained oil from an aqueous solution. As more aqueous solutions are used in industrial applications the risk of ground water contamination has increased. Stricter environmental rules and regulations are forcing these industries to recover contaminates from the ground water used in theses aqueous solutions before discharging the recovered water from their plants.
2. Description of the Related Art
Many devices have been proposed for coalescing oil from aqueous solutions. Such known apparatuses have not been completely satisfactory, primarily due to the difficulties associated with suspended solids contained in the fluid streams and the high cost of maintaining or replacing the coalescing media, the apparatus and/or the ability of the apparatus to adequately separate the immiscible liquids while still maintaining reliability and service factors. Such known apparatuses often perform an adequate separation function when suspended solids in the fluid stream are under five milligrams per liter. These same apparatuses have not been satisfactory for continuous flow processing when suspended solids are above five milligrams per liter without the use of expensive, high maintenance filtration systems or removing and manually cleaning the coalescing media. In high rate flow applications of up to 3,000 GPM, the coalescing media quickly fouls with accumulated solids and the recovery efficiencies are less than desirable considering the capital investment required for the equipment. In these high flow rate applications filtration is not practical due to the large quantity of suspended solids found in the process fluid stream which must be continually removed on a daily basis if one wishes to forestall fouling of the coalescing media.